Transcript Ecology
Ecology What is Ecology? • Study of interactions among 1. Organisms (LivingLiving) 2. Organisms and their environment (Living-Nonliving) Species- a group of similar organisms that can breed and produce fertile offspring. 3-2 Ecological Levels of Organization Section 3-1 Go to Section: Levels of Organization • Individual- one organism (living) • Ex a moose Levels of Organization • Population- groups of individuals that belong to the same species and live in the same area. (livingliving same species) • Ex many moose Levels of Organization • Community- groups of different populations (more than one population or different groups of species) Ex: many groups of moose, beavers, trees, grass (all living) Levels of Organization • Ecosystem- all organisms in a particular area along with the nonliving. (living and nonliving) Ex: many groups of moose, beavers, trees, grass, rocks, water, mountains Levels of Organization • Biome- group of ecosystems that have the same climate and similar dominant communities • Biomes: tropical rain forest, tropical dry forest, tropical savannah, temperate grassland, desert, temperate woodland and shrub land, temperate forest, northwestern coniferous forest, boreal forest (taiga), tundra, mountains and ice caps Levels of Organization • Biosphere- all of the planet where life exists, includes land, water, and, air • Life extends 8 km up and 11 km below the surface What shapes an ecosystem? • Biotic factors- • Abiotic factors- • Ex. Interactions • Ex. Temperature, biological (living) influences on ecosystem between organisms, predation, symbiosis, etc. nonliving influences on ecosystems precipitation, nutrient availability, soil type, sunlight. What are the roles of organisms in an ecosystem? • Habitat- an area where an organism lives • Niche- full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. – Includes where in the food chain it is, and where an organism feeds • Habitat is like an address in an ecosystem and a niche is like the job in an ecosystem. In an ecosystem, organisms need to be able to obtain energy. • Producers- make their own food • Consumers- get energy from consuming producers Producers • Capture energy from • sunlight or chemicals and use the energy to produce food. Producers are autotrophs- they make food from their environment Autotrophs convert food to energy in 2 ways: • Get energy from the sun by photosynthesis • Get energy without light by chemosynthesis Consumers • Consumers are heterotrophs- get energy from other organisms • Types of Consumers: – – – – Herbivores- eat only plants Carnivores- eat animals Omnivores- eat both plants and animals Detritivores (decomposers)- eat dead matter (plants and animals) Feeding Relationships • Energy flows through an ecosystem in one direction from: – – – – 1. the sun or inorganic compounds 2. To autotrophs (producers) 3. To heterotrophs (consumers) Decomposers get energy from decomposing dead organisms Food Chain- a series of steps in which organisms transfer energy by eating or being eaten. Food Web- A network of feeding relationships. (More realistic that a food chain) Trophic levels • Each step in a food chain or a food web is called a trophic level. – Producers are the first trophic level – Consumers are the second, third, or higher trophic level • Each trophic level depends on the one below for energy • Only part of the energy stored in one level can be passed to the next • Most energy is consumed for life processes (respiration, movement, etc., and heat is given off) Flow of Energy Energy Pyramid (cont’d) • Only 10% of the energy available within one trophic level is transferred to organisms in the next trophic level • Less than 1% is actually used by organisms on Earth Biomass Pyramid • Biomass- the total amount of living tissue within a given trophic level. • A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem. Biomass Pyramid 50 grams of lion tissue 500 grams of giraffe 5000 grams of greenery Pyramid of Numbers • Ecological pyramids can also be based on the numbers of individual organisms at each trophic level. • The pyramid of numbers shows the relative number of individual organisms at each trophic level. • Because each trophic level harvests only about 1/10th of the energy from the level below, it can support only about 1/10th the amount of living tissue.